Learning Objectives
  • Describe metabolic and nutritional changes 
   during critical illness.
  • Discuss nutrition assessment in the ICU 
   patients.
  • Review current guidelines for provision of 
   nutrition support in adult critically ill patients.
   Definition of a Critically Ill Patient
  • American Association of Critical-Care Nurses
   –“Critically ill patients are defined as those patients 
    who are at high risk for actual or potential life-
    threatening health problems. The more critically ill 
    the patient is, the more likely he or she is to be 
    highly vulnerable, unstable and complex, thereby 
    requiring intense and vigilant nursing care”.
                   Nutrition and Malnutrition 
                    in the Critically Ill Patient
     • Nutrition plays a key role for recovery from illness 
     • Up to 50% of critically ill patients have preexisting 
        nutritional disorders
     • Patients who are well nourished prior to ICU 
        admission, develop nutritional disorders rapidly
        –Metabolic demands of illness and healing
        –Rapid fluid shifts
        –Loss of specific vitamins and trace elements
     • Extent of muscle wasting and weight loss is inversely 
        correlated with long-term survival
                                                                        5
       Physiological Changes During Critical Illness 
        Imbalanced hormone 
       levels: catecholamines,         Excess liver glucose          Insulin resistance 
          cortisol, glucagon,              production 
      growth hormone, insulin 
                                                   Increased production of 
                        Excess catabolism              proinflammatory 
                                                           cytokines